Strongly thermochromic W-doped VO2 films with a large temperature coefficient of electrical resistance near room temperature

We report the crystal structure, surface morphology, electronic band structure, optical and electrical properties, and semiconductor-metal transition characteristics of strongly thermochromic W-doped VO 2 films with a large (up to -16 % K −1 ) temperature coefficient of electrical resistance at a small hysteresis width of electrical resistivity (down to 3 °C) near room temperature, and with a wide temperature operation range at a high detection sensitivity (≥ 8 % K −1 ) and low values of the electrical resistivity. They were deposited at a reduced substrate temperature of 350 °C onto soda-lime glass (SLG) with two versions of yttria-stabilized zirconia (YSZ) interlayers possessing different cubic crystal orientations, and onto bare SLG and monocrystalline YSZ and Al 2 O 3 substrates for comparison. The W-doped VO 2 depositions were performed using reactive deep oscillation magnetron sputtering with a feedback pulsed O 2 flow control allowing us to increase deposition rate of films up to 20–30 nm min −1 for a target-substrate distance of 100 mm. The results are important for a further improvement of thermochromic performance of VO 2 -based coatings for energy-saving smart windows and for a new design of high-performance infrared detectors and temperature sensors prepared by a fast low-temperature scalable synthesis.